This 28-year-old earns over $100,000 a month blogging and traveling full-time

After earning two undergraduate degrees and a Master's in finance, Michelle Schroeder-Gardner had racked up $38,000 worth of student loan debt.

She managed to pay it all off in just seven months, thanks largely to one key strategy: She shifted her focus to earning.

"I earned as much money as I could outside of my day job," writes Schroeder-Gardner, who was making $50,000 a year as a financial analyst at the time. "I mystery shopped and got paid to take surveys, but the biggest thing I did was I made an income through my blog."

She started her blog, "Making Sense of Cents," in 2011 when she was still in grad school but never intended on monetizing it. "I treated it more like a journal," the 28-year-old tells CNBC Make It. "It was all just a way to track my own financial progress so I could pay off my student loans and stop living paycheck to paycheck."

"It took around six months to make my first $100 from the blog," she continues, but "once I realized I could make money from it, it grew pretty quickly."

When she wasn't at work, Schroeder-Gardner was building a following, she says: "Any extra time I had would go towards growing my blog. I woke up early in the mornings, stayed up late at night, used lunch breaks at my day job, and I even used my vacation days to focus on my blog."

Courtesy of Michelle Schroeder-Gardner

Michelle Schroeder-Gardner and her husband Wes quit their jobs in 2013 and now travel full-time in an RV

The time and effort paid off: By 2013, she was bringing home an additional $10,000 a month from her blog. The extra income not only allowed her to pay off her loans but also to quit her job as a financial analyst.

Schroeder-Gardner has been blogging full-time since October 2013, when she left her day job. In 2016 alone, she made just less than $1 million. Today, she regularly earns over $100,000 a month.

There are three main ways her blog generates revenue:

1. Affiliate marketing, which is where the bulk of her income comes from, earns her about$50,000 a month.

2. Her affiliate marketing course, in which she teaches people how to make money online, earns her between$40,000 and $50,000 a month.

3. Advertising — including both sponsored advertisements with companies and display advertising — generates$12,000 to $23,000 a month.

Whether you're paying down debt or looking to achieve financial independence ASAP, focus on earning, Schroeder-Gardner advises: "While cutting your budget is great, usually there's a limit to how much you can save. Find ways to make more, because there's no limit on how much extra money you can make in your spare time."

Despite her financial success, she and her husband Wes, who also quit his job in 2013, live modestly. "We save and invest more than 85 percent of what we earn each month," she tells CNBC Make It.

They don't have a mortgage — they sold their house in Missouri in 2015 — and now travel across North America full-time in their RV.

On a typical day, the couple works for an hour or two in the morning, uses the daytime to explore, hike, or walk their two dogs and then logs a few more hours of work in the evening.

"To us, full-time RVing is freedom," Schroeder-Gardner writes. "We can chase good weather, we can visit friends and families all over the country, we can wake up one morning by the ocean, and spend the night next to a snow capped mountain. It also means that we understand how little we actually need to live, and that is true freedom."